<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }

        ul {
            list-style: none;
        }

        body {
            background: url(./images/wx.jpg) repeat-x;
        }

        .nav {
            height: 75px;
        }
        ul li{
            float: left;
            margin: 0 10px;
            padding-top: 21px;
        }

        a {
            display: inline-block;
            padding-left: 15px;
            height: 33px;
            background: url(./images/to.png) no-repeat;
            text-decoration: none;
            color: #fff;
            font-size: 14px;
            line-height: 33px;
        }

        span {
            display: inline-block;
            padding-right: 15px;
            background: url(./images/to.png) no-repeat;
            background-position: right;
        }
        
        a:hover{
            background-image: url(./images/ao.png);
        }

        a:hover span{
            background-image: url(./images/ao.png);
        }

    </style>
</head>

<body>
    <div class="nav">
        <ul>
            <li><a href="#"><span>首页中心</span></a></li>
            <li><a href="#"><span>游戏中心</span></a></li>
            <li><a href="#"><span>帮助中心</span></a></li>
            <li><a href="#"><span>防沉迷中心</span></a></li>
        </ul>
    </div>
</body>

</html>